The final box office for Hulk was USD $132 million in the US and USD $113 worldwide, for a combined total of USD $245 million. 
Lou Ferrigno, who played the Hulk in "The Incredible Hulk" (1978), has a cameo in this film as a security guard. He reprised the role in The Incredible Hulk (2008).
Mychael Danna was originally hired to write the musical score, but later replaced by Danny Elfman.
Ang Lee turned down Terminator 3: Rise of the Machines (2003) to direct this film.
Nick Nolte was always the producers' first choice to play Bruce Banner's father.
In development for 12 years, sufficient time for CGI to become sophisticated enough to render the special effects needed.
Creating the Hulk in CGI was one of the most complex tasks Industrial Light & Magic had ever undertaken at that time. The computer model used 12996 texture maps, and required 1165 muscle movements and 100 layers of skin. It took the combined work and efforts of about 180 ILM technicians (69 technical artists, 41 animators, 35 compositors, 10 muscle action animators, 9 CG modellers, 8 supervisors, 6 skin painters and 5 motion-capture wranglers), over 2.5 million hours and one and a half years for him to be effectively created and portrayed in the film. With all that work, some of the public complained that the Hulk looked too fake, comparing him with Shrek (2001).
The word "hulk" is used only once in the film, by Banner.
One of the rules that the costume design team were set was "no lab coats".
It was a deliberate decision to withhold showing Hulk in daylight until much later into the film, giving the audience the chance to get used to seeing him.
The amount of CGI involved in the scene where Hulk battles the three mutant dogs was one of the hardest, most complicated scenes ILM had ever done. Ultimately what ended up on screen was only a third of what was originally storyboarded. To have filmed all of it would have been simply too expensive.
The graphic map of the military complex took three months to perfect.
ILM wanted to study a human performing the actions Hulk does in order to create his movements. Initially they tried this using body-builders but found them to be too cumbersome. Instead they settled for personal trainers.
Stan Lee, the creator of the Hulk in 1962, has a cameo in this film as a security guard. Lee ad-libbed his lines.
When the project was in the works in the mid-1990s Johnny Depp was originally the top choice to play Bruce Banner. Later on, Billy Crudup was Ang Lee's first choice to play Banner, but the actor declined the offer. Then Tom Cruise was offered the role of Bruce Banner, and then Steve Buscemi, David Duchovny and Jeff Goldblum were tested for the role before finally Eric Bana was cast. Edward Norton was approached to play Bruce Banner, but turned it down. He later accepted the role in The Incredible Hulk (2008).
Ang Lee performed the Hulk himself using motion capture technology.
Jennifer Connelly was attracted to the role of Betty Ross, since she found Ang Lee's vision of the Hulk interesting: "He wasn't talking about a glossy fun-filled kids' movie about a green guy running around in tights. He was talking along the lines of tragedy and psychodrama, the green monster of rage, greed, jealousy and fear in all of us."
To prepare for his role as General Ross, Sam Elliot read the Hulk comic books. He had doubts about growing a mustache, since the Army doesn't encourage facial hair, but was convinced by Ang Lee to do so.
Sam Elliot accepted the role of General Ross without reading the script, being simply excited to work with Ang Lee.
Eric Bana commented that the mood during shooting was "ridiculously serious and morbid." Ang Lee explained to him that he was shooting a sort of superhero tragedy and he would be making a whole other movie about the Hulk at the Industrial Light and Magic studios. Ironically, the film was criticized as being an overly serious superhero film.
According to director Ang Lee, the film's screenplay drew influences from monster tales like King Kong and Frankenstein; fantasies like Dr. Jekyll & Mr. Hyde, Beauty & the Beast and Faust; and most particularly Greek mythological tragedies.
Ang Lee took Eric Bana to watch a bare-knuckled boxing match to prepare him for the brutality of his role.
When Bruce is struck by gamma radiation, there is a zoom-in shot of his eye, and seen in its reflective surface is a gamma-bomb explosion. This image was seen in "The Incredible Hulk" (1982), on every occasion right before Bruce Banner transformed into the Hulk.
Among the many writers who contributed to the film's screenplay were Michael France, John Turman, Jonathan Hensleigh, Zak Penn, J.J. Abrams, the partnership of Scott Alexander and Larry Karaszewski, Michael Tolkin, David Hayter, and James Schamus. However, only France, Turman and Schamus received final credit, as their concepts primarily featured in the final film.
According to Michael France, he wrote the film's screenplay three times.
An early draft of the script, written by Jonathan Hensleigh in August 1997, had Bruce Banner performing experiments with gamma-irradiated insect DNA on convicts, transforming them into insect-men whom the Hulk then battles.
Ang Lee's son designed the "hulk dogs" that attack the Hulk.
According to Ang Lee's DVD commentary, the dogfight scene in the woods was originally envisioned with the Hulk fighting the monster dogs while naked. However, this was thought to be too difficult for a PG-13 movie, and so the Hulk doesn't appear naked until the very end of the fight.
The house used by Betty Ross was also used in To Kill a Mockingbird (1962).
To show the cast where Hulk would be standing (after being added by CGI), a cardboard cutout was used. The cut-out was nicknamed "Elvis on a stick" by the cast and crew.
When Betty first meets David Banner, they discuss a man named Benny. Benny was a soldier who appeared in the Hulk graphic novel "The Dogs of War" which introduced the concept of Hulk dogs (which appear in this film).
During a scene early in the movie while Betty is on the phone you can see a poster for "Eat Drink Man Woman" (Yin shi nan nu (1994)) in the background, also directed by Ang Lee.
Holds the record for largest second weekend box office drop for a film that opened at #1, with a -69.7% drop.
During the opening credits when the Marvel logo appears, pages from a Hulk comic book are quickly flipped in the background. These pages are from the Hulk graphic novel 'Dogs of War'.
When the first Hulk-out (transformation of Banner into Hulk) occurs the color of the Hulk is either gray or greenish-gray. This is in homage to the first appearance of Hulk when he was actually gray in his debut comic (May 1962). The publisher couldn't do gray very well so Stan Lee changed the color to green, simply because green hadn't been used much by other characters. From the second Hulk-out he maintains his prominent emerald hue.
In this film, the madder the Hulk gets, the larger he becomes. The first time he appears, he is 9 feet tall, the second time he is 12 feet and the third time he is 15 feet tall. His skin would also be colored grayish-green in his first appearance, and afterwards remain greenish. The ILM animators thus had to create three distinctly different Hulks.
According to the animators at Industrial Light & Magic, the Hulk weighs 3452 lbs, and can exert 14 tons of pressure/inch2. His skin is 10 times as strong as Kevlar. His chest measures 208 inches, his waist 130 inches, his foot 51 inches and his neck 81 inches. If he wore shoes, they would be size 87. He can move at a top speed of 300 mph and cross 3-4 miles in a single jump.
In the Hulk comics, Bruce Banner's father was named Brian Banner. He was renamed David Banner in this film as a tribute to "The Incredible Hulk" (1978), where the Hulk was known as David Banner.
The helicopters that attack the Hulk in the desert are RAH-66 Comanches. The jets he fights near the Golden Gate Bridge are F/A-22 Raptors. At the time of the film's release, neither aircraft were in active service with any branch of the US military. The RAH-66 program has subsequently been scrapped (on 23 February 2004), with no helicopters ever entering active service.
Nick Nolte had his hair grown wildly for this movie when he was arrested on drunk driving charges and photographed for his now infamous mug shot.
The gammasphere in the film actually exists, located in ATLAS (Argonne Tandem Linear Accelerator) at Argonne National Laboratory in Argonne, Illinois. However, it has no gamma-generating capabilities.
One of the scenes deleted from the final cut was a cameo by Willie Brown, at the time the mayor of San Francisco, playing himself and talking to General Ross on the phone.
Bruce's dreams are primarily colored green and purple, the distinctive colors of the Hulk, who has green skin and wears purple pants.
Eric Bana was cast on the strength of his vicious performance in Chopper (2000).
Danny Elfman's musical score pays homage to composer Bernard Herrmann's work with suspense director Sir Alfred Hitchcock.
Ang Lee employed the split-screen technique to cinematically mimic the panels of a comic-book page. This required many takes of one scene, which was draining for Eric Bana: it took him four takes to film Banner's first Hulk-out, and by the time of its completion he was on the verge of collapse.
Costume designer Marit Allen had to come up with unflattering, nerdy clothes for Bruce Banner to disguise the fact that Eric Bana was actually in perfect shape.
When General Ross heads towards San Francisco to intercept the Hulk his helicopter is code-named "T-Bolt." This is a homage to Ross's nickname "Thunderbolt" (for his explosive temper) in the comics.
Both Sam Elliott and Rebecca Romijn have played major and supporting roles as different characters throughout the Marvel Universe. Elliott played a major role as Gen. Ross in this film and a supporting role as the Caretaker in Ghost Rider (2007). Rebecca Romijn had a major role as Mystique in all 3 X-Men movies, and played a supporting role as Joan (Frank's neighbor) in The Punisher (2004).
The first production to be filmed in the Mountain Home Demonstration State Forest within the Sequoia National Forest, outside of Springville, CA.
During production in San Francisco, filming had to be stopped for about two hours because some college students from UC Berkeley were playing a prank and systematically urinating in porta-potties, creating very loud peeing sounds that distracted the actors on set. It took about two hours to round up all of the students.
The Abrams tanks that confront the Hulk in the desert are in fact former British Army Chieftain tanks that were dressed to represent the Abrams. The mock-ups are very convincing and quite difficult to spot. The Chieftain has six wheels per side, whereas the Abrams has seven.
Eric Bana was not a fan of the Hulk comics, which this film is based on, but he was a big fan of "The Incredible Hulk" (1978), which the sequel was based on.
Betty Ross is played in this film by Jennifer Connelly. In The Incredible Hulk (2008), she is replaced by Liv Tyler, who played her on-screen sister in Inventing the Abbotts (1997).
This film features the only combat missions ever flown (albeit simulated and fictional) by the RAH-66 Comanche stealth helicopter, whose program was canceled a year after the film's premiere with only two copies built.
At the end of The Incredible Hulk (2008), in the cabin when Bruce is writing a letter, another letter can be seen with the name "David Banner" on it.